28 March 2014

In an effort to reduce further the already low risk of a Model S battery fire resulting from impact with road debris, Tesla Motors is outfitting new Model S cars (as of 6 March) with an underbody triple shield system consisting first of an aluminum bar; then a titanium shield; and finally a shallow angle solid aluminum extrusion.

Tesla will also retrofit the system, free of charge, to existing Model S cars upon request or as part of a normally scheduled service, wrote Tesla Motors CEO Elon Musk in a post on the Internet publishing site Medium. The action comes as an additional Tesla response in the wake of the two widely-reported Model S collisions in 2013 that resulted in underbody damage that led to car fires. Tesla had earlier provided an over-the-air software update to increase the default ground clearance of the Model S at highway speeds, thereby also reducing the odds of a severe underbody impact.

During the course of 152 vehicle level tests, the shields prevented any damage that could cause a fire or penetrate the existing quarter inch of ballistic grade aluminum armor plate that already protects the battery pack. We have tried every worst case debris impact we can think of, including hardened steel structures set in the ideal position for a piking event, essentially equivalent to driving a car at highway speed into a steel spear braced on the tarmac.

—Elon Musk

The rounded, hollow aluminum bar that is the first in the new line of defense is designed either to deflect objects entirely or, in the case of a self-stabilizing, ultra-high-strength object such as a three-ball steel tow hitch, absorb the impact and force it upwards forward of the battery pack. While this would pierce the plastic aeroshield and front trunk liner, the impact would cause no damage affecting safety. The car remains drivable during and after the impact.

The titanium plate is designed to protect sensitive front underbody components from being damaged and also aids in neutralizing the road debris.

The shallow angle solid aluminum extrusion is intended to handle any piece of road debris that has not already been deflected or crushed. The extrusion further absorbs impact energy, and ultimately would cause the Model S to ramp up and over the object should it prove incompressible or immovable.

Tesla also published three slow motion videos provided by on-vehicle high-speed cameras of a newly outfitted Model S destroying or deflecting potentially dangerous road debris: a three-ball tow hitch; a concrete block; and an alternator.

Musk said that the new shield system has only a 0.1% impact on range and does not affect ride or handling. Wind tunnel testing showed no discernible change in drag or lift on the car.

@E-P, I have long been a proponent of a generator-trailer for EV range extension for trips. It can also be used as an emergency generator on wheels for homes. I checked out the tzero site, but found no info on the trailer. Was that also an experimental item, or has there been further development?

"Summer is almost here, and thousands of US travelers are gearing up for the great American tradition of road tripping across the States. But what if those trips could be taken by electric cars instead of pollution-spewing gas vehicles? Norman Hajjar is setting out to prove once and for all that electric cars can go the distance by driving a Tesla Model S on a record-breaking 12,000-mile trip across the USA!

The trip is sponsored by electric vehicle software and information services company Recargo Inc., and Norman Hajjar is the Managing Director of its driver research division. As of yesterday Norman had reached Florida, and he’s currently making his way back to the West Coast. The 18-day 12,000-mile journey is set to span the four corners of the lower 48 states: Washington, Maine, Florida, and California, ending at Recargo’s offices in Venice, California.

Before the arrival of the Tesla Model S, electric cars were hampered by low driving ranges and slow charging times. The Tesla Model S has a 250+ mile range, and thanks to Tesla’s nationwide “Supercharger” charging network, the Model S’s battery can be recharged in under 30 minutes.

Related: Tesla Supercharging Stations Enable Effortless Travel from LA to New York

“We’re attempting this record-breaking journey to illustrate a historic point: With a robust network of fast charging locations, you can drive an electric car wherever you want without using a drop of gasoline,” explained Brian Kariger, CEO of Recargo. “Daily commutes and cross-country trips alike are now made better by driving electric.”

The trip is also an attempt to show how the public needs more access to “fast chargers,” which would make it easier for EV drivers to keep their electric cars on the road. “We’ve conducted studies of thousands of EV drivers, and it’s clear they want to be able to fuel with the same quick ‘pit-stop practicality’ that gas car drivers enjoy at service stations. Give them that, and we believe the category will truly blossom,” Norman Hajjar stated."

You can continue to follow along on Norman’s trip via live updates from the road at http://roadtrip.plugshare.com/